Overhead conveyor chains are used in numerous manufacturing and processing industries. They comprise links joined by link pins, and include bearing wheels which ride on supporting tracks. They may extend for several hundred to several thousand feet. A typical cost of a new chain is $60 per foot. Accordingly, manufacturers and processors like to maintain the useful life of a chain as much as possible. 14 years is a typical chain life.
One limiting factor on chain life is loosening of the swage connection of the bearing wheel axel to the inner race of the bearing wheel on either side of a chain link. This requires replacement of the affected wheels. Another limiting factor is wear on the link pins, which eventually have to be replaced.
Chains suffering from link pin wear are often repaired by using a “come along” secured at its opposite ends to spaced portions on the conveyor chain. The “come along” is tightened against the take up force applied to the chain. This loosens the chain between the come along securing points, allowing the removal and replacement of worn parts.
Where extensive repairs are required, the entire chain may be removed from its track. Worn pins, wheels or other components are removed and replaced with new counterparts. The cost to remove and either repair or replace chain is significant, e.g. $10-$12 per foot. The process typically takes 24 hours, 12 hours to remove, and 12 hours or more to repair or replace with a new chain, and if repaired, 12 hours more to replace the repaired chain. In addition, 36 hours of production down time means 36 hours of lost profit.